Safety helmet

ABSTRACT

A safety helmet includes a lower rear semi-spherical section adapted to slide over an upper semi-spherical section in response to a high impact accident causing flexure of the wearer&#39;&#39;s neck. The first section is pivoted to the second section about an axis which is located as nearly as possible to the normal pivot of the cervical skull axis. Position stops are provided to limit the downward and upward pivotal movement of the lower section. The lower edge of the lower section is broadly flanged and well padded to diversify and cushion impact with the neck of the wearer and is designed to engage the wearer&#39;&#39;s neck at a point below the fragile upper cervical area and, in particular, below the third vertebra.

United States Patent 1191 Brown et al.

[ Jan. 21, 1975 SAFETY HELMET [76] Inventors: Clarence Eugene Brown, 211

Watson Blvd., Centerville Ga. 31093; William A. Stephens, 2937 CristlineDr., Macon, Ga. 31204 [22] Filed: Mar. 19, 1973 [2]] Appl. No.: 342,416

[52] US. Cl 2/3 R [51] Int. Cl A42b 1/08 [58] Field of Search 2/3 R, 5,6, 8, 9, 10

[56] References Cited UNITED STATES PATENTS 2,017,059 10/1935 Gingg 2/82,860,343 11/1958 Aileo 2/6 X 2,861,274 11/1958 Stuart et a1 2/63,139,623 7/1964 Joseph, Jr 2/3 R 3,230,544 l/1966 Mager 2/3 R 3,242,5003/1966 Derr 2/3 R 3,383,706 5/1968 Lobelle 2/6 [5 7] ABSTRACT A safetyhelmet includes a lower rear semi-spherical section adapted to slideover an upper semi-spherical section in response to a high impactaccident causing flexure of the wearers neck. The first section ispivoted to the second section about an axis which is located as nearlyas possible to the normal pivot of the cervical skull axis. Positionstops are provided to limit the downward and upward pivotal movement ofthe lower section. The lower edge of the lower section is broadlyflanged and well padded to diversify and cushion impact with the neck ofthe wearer and is designed to engage the wearers neck at a point belowthe fragile upper cervical area and, in particular, below the thirdvertebra.

13 Claims, 4 Drawing Figures SAFETY HELMET BACKGROUND OF THE INVENTIONThis invention relates to safety helmets and is particularly concernedwith safety helmets which are designed to prevent excessive injury tothe neck and vertebrae of the wearer.

Safety helmets have come into wide use in response to the danger ofserious injury to motorcycle drivers and drivers in automotive races. Inthe past, such safety helmets have become substantially standardized andconsist of substantially semi-spherical shells of a suitable, rigid anddurable material, such as a high impact plastic or fiberglassimpregnated with resin. The shells are provided with suitable paddingabout their interiors to engage on and about the head.

While such safety helmets are extremely effective in protecting awearers head against injury, they fail to protect the wearer againstserious neck injuries and, indeed, due to the structure of such helmets,they materially increase the possibility or likelihood of neck injuries.The relatively narrow lower rear edge of the helmet has a tendency toengage the neck of the wearer in response to accidents which cause thehead and neck of the wearer to become suddenly and forciblyhyperextended. At this time, the helmet becomes a lethal piece ofequipment, the lower edge impinging on the first cervical vertebra,shoving it anteriorly and thus fracturing the odontoid and proceedingforwardly to transect the spinal cord at the C-1 level. This will leavethe individual decerebrate with the final outcome, death, occurringwithin a few hours. There have been proposals in the prior art whichhave been concerned with avoiding such injuries. In U.S. Pat. No.3,591,863, for example, it is proposed to provide an elongate,vertically extending neck pad engagable with the back of the wearersneck and shaped to conform to the wearers neck when the wearers head istipped and his neck is flexed backwardly a predetermined extent toprovide support to the cervical portion of the wearers spine andoccipital portion of the wearers skull. However, the mounting means forthe pad includes an arm depending downwardly and forwardly from thelower rear edge portion of the helmet which normally engages the rearside of the pad and a downwardly depending flexible strap for supportingthe pad. Since the arm and strap are engaged with the pad and the pad isengaged with the wearers neck, there is no delay in the impact time withthe result that even a minor impact will cause increased pressureagainst the wearers neck. A more severe accident may result in failureof the pad driving the narrow lower edge of the arm or the lower end ofthe strap, which are relatively close to the wearers neck to begin with,into the wearers neck causing injury to the cervical area. Moreover, ahelmet of this character is inherently uncomfortable because of thechafing and irritation caused by the pad always in engagement with theback of the wearers neck.

In US. Pat. No. 3,230,544 it is proposed to provide athletic headgearwith a hinged rear flap which has the purpose of avoiding the impact ofthe rear rim of the helmet on the back of the neck. However, this helmetis subject to a number of limitations making it unsuitable forprotection against injury in high impact accidents. The rearwardlyextending flap will, when extended, offer no side protection for the cutout area during impact. Moreover, the lower edge of the hinge wouldprovide a critical cutting edge to the wearers spine. There is no meansfor stopping the rearward movement of the flap, thus resulting inexcessive flexure of the wearers neck. In addition, the hinged flap ismaintained in engagement with the wearers neck causing chafing andirritation thereto. Also. in a dorsalforwards projected fall, the hingedflap could be projected forwardly and sever the spinal column or evendecapitate the wearer.

It has also been proposed in the prior art to provide a protectivehelmet of the hard hat type with pivoted sections. This is shown in US.Pat. No. 3,514,787. However, the purpose of the pivoted sections in thispatent is to provide a protective hat which can be collapsed to a moreportable condition. When the hat is used it is latched in its full openposition and thus, the several sections will be maintained in theirextended position during the impact of an accident.

SUMMARY OF THE INVENTION It is accordingly the principal object of thepresent invention to provide an improved safety helmet which avoids thedrawbacks and limitations of the prior art.

More particularly, it is an object ofthe present invention to provide'animproved safety helmet which reduces the possibility of injury to theneck and spine of the wearer during accidents which cause hyperextensionof the wearers neck.

To this end, the invention contemplates the provision of a safety helmethaving a pair of semi-spherical sections. A first semi-spherical sectionis provided to pro tect the upper portion of the wearers head, and asecond semi-spherical section, which is pivoted to the first section, isintended to protect the lower rear portion of the wearer's head. Thesecond section is slidably engaged with a semi-spherical surface of thefirst section, and pivots upwardly in response to the forces generatedduring hyperextension of the wearers neck during a high impact accident.For this purpose, the pivot axis for the second section is located asnearly as possible to the normal pivot of the cervical skull axis of thewearer. A spring is provided to bias the lower section downwardly to aposition protecting the lower rear portion of the wearers head, and apair of stops are provided to limit upward and downward movement of thesecond section. The upward movement is limited so that flexure of thewearers neck will be less than 50. The lower edge of the second sectionis broadly flanged and well padded to broaden and cushion the impactagainst the wearers neck. Moreover, the lower edge is so positioned thatimpact will be well below the fragile upper cervical area and will, inparticular, engage the wearers neck below the third vertebra.

These and other objects, features, and advantages of the presentinvention will become more readily apparent upon detailed considerationof the following description of a preferred embodiment with reference tothe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of asafety helmet of the present invention;

FIG. 2 is a vertical section view of a helmet of the present inventionpositioned on the head of a wearer whose skull and spinal column areshown in phantom line;

FIG. 3 is a partial section view taken along the line 3 3 of FIG. 2; and

FIG. 4 is a partial section view taken along the line 4 4 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to thedrawings, it will be seen that a helmet of the present inventionincludes a first helmet section 12 to which is pivoted a second helmetsection 14. Helmet section 12 is adapted to cover the top and sides ofthe wearers head and includes a semi-spherical shell portion 16 made ofa durable high impact plastic, such as resin impregnated fiberglass orpolycarbonate. Section 12 includes a raised portion 18 facilitating theflow of ventilating air into the helmet as will be presently described.For this purpose, raised portion 18 has a front wall 20 provided with aplurality of openings 22 for admitting ventilating air into the helmet.In order to control the flow of ventilating air, a control valve 24 isprovided in the form of a plate having a plurality of correspondingopenings which are slidable into alignment with openings 22 to open theopenings or out of alignment with openings 22 to close the openings. Inorder to move slide 24, a handle projects upwardly through a slot 28provided in the top wall of raised section 18.

The inner surface of helmet section 12 is lined with a padding 30adapted to tit and protect the wearers head. This padding is made from afoam plastic material or a foam rubber and serves to cushion impact.Padding 30 includes a plurality of ribs 32 within raised helmet section18, ribs 32 being separated by grooves 34. This ribbed design securesthe helmet on the wearer's head much in the fashion of tire treadssecuring a car to the road.

An important feature of helmet section 12 is the provision of a shoulder36 extending upwardly from semispherical section 16 at the rear ofraised section 18. As will be presently explained, shoulder 36 willserve as an abutment stop to limit upward movement of helmet section 14.In order to limit downward movement of helmet section 14, a second stopis provided in the form of a plurality of spaced, raised protuberances38 adjacent the rear edge of helmet section 12.

Helmet section 14 is adapted to cover the rear portion of the wearershead. This section is also formed of a high impact plastic, such asresin impregnated fiberglass or polycarbonate. This section alsoincludes a semi-spherical portion 40. A lip 42 extends downwardly fromthe upper edge of section 40 and serves to engage with stops 38 whenhelmet section 14 is in its lowered position and engage against shoulder36 when helmet section 14 is in its upper position, as will be presentlyexplained.

Helmet section 14 includes a broad lower flange 44 which serves tobroaden the impact of the lower edge of the helmet against the neck ofthe wearer in a high impact accident which causes hyperextension of thewearers neck. Helmet section 14 is also lined with padding 46 made ofthe same foam cushioning material as is used to line helmet section 12.It is to be noted that padding 46 includes a lower thickened lip portion48 beneath broad flange 44, serving to provide greater protection to thewearers neck upon impact therewith.

Lower helmet section 14 is pivoted on a pair of pivots 50, only one ofwhich is seen in FIGS. 1 and 2, provided on both sides of the helmet.Pivots 50 define an axis which coincides with a central axis of thesemispherical surfaces of sections 12 and 14 and is positioned as nearlyas possible to the normal pivot of the cervical skull axis of thewearer. This axis extends more or less through the opening of one ear tothe opening of the other ear of most individuals.

It will be noted that the semi-spherical shape of helmet portion 40 ofsection 14 and padding 46 closely conforms to the semi-spherical shapeof helmet portion 16. For this reason, lower helmet section 14 isadapted to slide along the outer surface of semi-spherical portion 16 ofupper helmet section 12. In order to facilitate this sliding movement,padding 46 is provided with a plurality of grooves 52 which receive thestop projections 38 extending upwardly from the lower edge of upperhelmet section 12.

A torsion spring 54 extends around each pivot 50 and includes a firstarm 56 engaged against a stop 58 provided on the inner surface of upperhelmet section 12 and a second arm 60 having an end engaged against astop 62 provided on lower helmet section 14. Spring 54 normally biasessection 14 to its lower position with lip 42 engaged against stopprotuberances 38. When, however, the wearer is involved in an accidentcausing a whip-lash movement of his head, his head will pivot backwardlyto engage the broad flange padding 48 against the back of his neck. Thiswill cause lower helmet section 14 to pivot upwardly against the bias ofthe spring until lip 42 engages shoulder 36. The position of theshoulder 36 is selected so that the head will flex less than 50. It hasbeen found that flexure of the neck beyond fifty degrees may causecritical or fatal injury.

The broad lower flange 44 of lower helmet section 14 is so positionedthat it will impact against the neck of the wearer at a point well belowthe fragile upper cervical area in a lower stronger cervical area. Inparticular, it has been found that danger of serious, and fatal,injuries is greatly reduced if the impact is provided below the thirdvertebra.

Helmet 10 is provided with a pair of chin straps 64 and 66 which areattached at one end to pivots 50. A buckle fixture 68 is provided at oneend of strap 66 so that the chin strap may be securely fastened when thehelmet is in place on the wearers head.

The use of the helmet 10 of the present invention will be bestunderstood with reference to FIG. 2. In this figure helmet 10 is shownpositioned on the head of the wearer. The semispherical shape of helmetsection 14 corresponds closely to the semi-spherical shape of thewearers skull 70. In normal use, lower helmet section 14 is biaseddownwardly to the lower position as shown in FIG. 2 with lip 42 engagedagainst stop protuberances 38. If, at this time, the wearer is involvedin an accident causing hyper-extension of his neck in a whiplashfashion, his skull 70 will be pivoted backwardly until the broad flangepadding 48 engages against his neck. It is an important feature of thepresent inven tion, that the position of broad lower flange 44 andpadding 48 is such that this engagement occurs below the upper fragilecervical area. In particular, engagement against the first vertebra 72,the second vertebra 74, or the third vertebra 76 is avoided andengagement with the wearer's neck is in the region of the fourthvertebra 78 or lower. As was explained hereinabove, a problem with priorart helmets resided in the fact that the lower, relatively narrow, edgeof the helmet would engage against one of the upper vertebra, causingfatal or serious injury to the wearer. By confining impact to a pointbelow the third vertebra, the present invention serves greatly to reduceserious injuries. Moreover the broad area of impact provided by broadflange portion 44 results in a sharp reduction in the damage of acritical and/or fatal injury.

While a specific embodiment of the invention has been described herein,it is to be understood that modifications, substitutions and equivalentsmay be used without departing from the scope of the inventive concept.

The invention claimed is:

l. A safety helmet comprising:

a first semi-spherical helmet section adapted to cover the top portionof the wearer's head;

a second semi-spherical helmet section adapted to cover the lower backportion of the wearers head, said first section being nested within saidsecond section with the lower edge of said second section forming thelower rear edge of said helmet and the upper edge of said second sectionbeing engaged on the lower portion of said first section, and pivotmeans for pivotally connecting said second section to said first sectionabout an axis coinciding with a central axis of the first and secondsections whereby the second section is slidable over a semisphericalsurface of said first section;

means for biasing said second section downwardly to a position coveringthe lower rear portion of the wearers head, said second section, inresponse to a high impact accident causing whip-lash of the wearershead, pivoting upwardly in sliding engagement with said first section tominimize injury to the neck of the wearer; and

stop means interacting between said first and second sections to limitpivotal motion between said sections such that the lower edge of saidsecond section cannot reach the position of the lower edge of said firstsection, said lower edge of the second section being in the form of animpact-absorbing flange to prevent injury to the wearer.

2. A safety helmet as recited in claim 1, wherein said second section ispivoted to said first section about a pivot axis which is located asnear as possible to the cervical skull axis of the wearer.

3. A safety helmet as recited in claim 1, wherein first stop meanslimits downward movement of said second section relative to said firstsection and second stop means limits upward movement of said secondsection relative to said first section.

4. A safety helmet as recited in claim 3, wherein said second stop meansis so positioned that said lower edge of the second section is stoppedrelative to said first section at a predetermined position whichcorresponds to flexing of the wearers neck to less than 50.

5. A safety helmet as recited in claim 1, wherein said broad flange iscovered with substantial padding to cushion impact with the wearersneck.

6. A safety helmet as recited in claim 5, wherein said lower edge is sopositioned that it will engage the wearers neck at a point below theupper fragile cervical area.

7. A safety helmet as recited in claim 6, wherein said point ofengagement of said lower edge is below the third cervical vertebra.

8. A safety helmet as recited in claim 6, wherein said second section ispivoted to said first section about a pivot axis which is located asnear as possible to the cervical skull axis of the wearer.

9. A safety helmet as recited in claim 6, wherein first stop meanslimits downward movement of said second section relative to said firstsection and second stop means limits upward movement of said secondsection relative to said first section.

10. A safety helmet as recited in claim 9, wherein said section stopmeans is so positioned that said lower edge of the second section isstopped relative to said first section at a predetermined position whichcorresponds to flexing of the wearers neck to less than 50.

11. A safety helmet comprising, in combination:

a pair of helmet sections disposed in nested relation so as to provideinner and outer helmet sections, said inner section having a top portionand a rear portion in which said rear portion presents an outerpart-spherical surface of generally sectorial form. said outer helmetsection being of part-spherical, sectorial form;

means connecting the inner and outer sections about a pivot axiscoinciding with the central axis of said sectorial surface of the innersection and of said sectorial surface of the outer section for allowingsaid outer section to swing about said pivot axis relative to said innersection;

said rear portion of the inner section having a free marginal edgeportion overlapped by said outer section, first stop means extendingalong said free marginal edge portion and second stop means extendingalong a path parallel to but spaced from said first stop means;

said outer section having a lower edge portion presenting animpact-absorbing flange and an upper marginal edge portion, and abutmentmeans along said upper marginal edge portion for engaging said first andsecond stop means to establish respectively a normal and an abnormalposition of said outer section with respect to said inner section, saidouter section being of a width greater than the spacing between saidfirst and second stop means whereby said impact-absorbing flange isdisposed outwardly beyond said free marginal edge portion of the innersection when said abutment means is in engagement with said second stopmeans; and

means normally maintaining said abutment means against said first stopmeans for resisting movement of said outer section to said abnormalposition thereof.

12. A safety helmet as defined in claim 11 wherein said means normallymaintaining said abutment means against said first stop means comprisesa spring biasing said abutment means against said first stop meanswhereby said outer section moves against increasing spring reactionforce as said abutment means approaches said second stop means.

13. A safety helmet as defined in claim 12 wherein said first stop meansis in the form of spaced projections and said outer section includes apadding liner having grooves receiving said projections.

1. A safety helmet comprising: a first semi-spherical helmet sectionadapted to cover the top portion of the wearer''s head; a secondsemi-spherical helmet section adapted to cover the lower back portion ofthe wearer''s head, said first section being nested within said secondsection with the lower edge of said second section forming the lowerrear edge of said helmet and the upper edge of said second section beingengaged on the lower portion of said first section, and pivot means forpivotally connecting said second section to said first section about anaxis coinciding with a central axis of the first and second sectionswhereby the second section is slidable over a semi-spherical surface ofsaid first section; means for biasing said second section downwardly toa position covering the lower rear portion of the wearer''s head, saidsecond section, in response to a high impact accident causing whip-lashof the wearer''s head, pivoting upwardly in sliding engagement with saidfirst section to minimize injury to the neck of the wearer; and stopmeans interacting between said first and second sections to limitpivotal motion between said sections such that the lower edge of saidsecond section cannot reach the position of the lower edge of said firstsection, said lower edge of the second section being in the form of animpact-absorbing flange to prevent injury to the wearer.
 2. A safetyhelmet as recited in claim 1, wherein said second section is pivoted tosaid first section about a pivot axis which is located as near aspossible to the cervical skull axis of the wearer.
 3. A safety helmet asrecited in claim 1, wherein first stop means limits downward movement ofsaid second section relative to said first section and second stop meanslimits upward movement of said second section relative to said firstsection.
 4. A safety helmet as recited in claim 3, wherein said secondstop means is so positioned that said lower edge of the second sectionis stopped relative to said first section at a predetermined positionwhich corresponds to flexing of the wearer''s neck to less than 50*. 5.A safety helmet as recited in claim 1, wherein said broad flange iscovered with substantial padding to cushion impact with the wearer''sneck.
 6. A safety helmet as recited in claim 5, wherein said lower edgeis so positioned that it will engage the wearer''s neck at a point belowthe upper fragile cervical area.
 7. A safety helmet as recited in claim6, wherein said point of engagement of said lower edge is below thethird cervical vertebra.
 8. A safety helmet as recited in claim 6,wherein said second section is pivoted to said first section about apivot axis which is located as near as possible to the cervical skullaxis of the wearer.
 9. A safety helmet as recited in claim 6, whereinfirst stop means limits downward movement of said second sectionrelative to said first section and second stop means limits upwardmovement of said second section relative to said first section.
 10. Asafety helmet as recited in claim 9, wherein said section stop means isso positioned that said lower edge of the second section is stoppedrelative to said first section at a predetermined position whichcorresponds to flexing of the wearer''s neck to less than 50*.
 11. Asafety helmet comprising, in combination: a pair of helmet sectionsdisposed in nested relation so as to provide inner and outer helmetsections, said inner section having a top portion and a rear portion inwhich said rear portion presents an outer part-spherical surface ofgenerally sectorial form, said outer helmet section being ofpart-spherical, sectorial form; means connecting the inner and outersections about a pivot axis coinciding with the central axis of saidsectorial surface of the inner section and of said sectorial surface ofthe outer section for allowing said outer section to swing about saidpivot axis relative to said inner section; said rear portion of theinner section having a free marginal edge portion overlapped by saidouter section, first stop means extending along said free marginal edgeportion and second stop means extending along a path parallel to butspaced from said first stop means; said outer section having a loweredge portion presenting an impact-absorbing flange and an upper marginaledge portion, and abutment means along said upper marginal edge portionfor engaging said first and second stop means to establish respectivelya normal and an abnormal position of said outer section with respect tosaid inner section, said outer section being of a width greater than thespacing between said first and second stop means whereby saidimpact-absorbing flange is disposed outwardly beyond said free marginaledge portion of the inner section when said abutment means is inengagement with said second stop means; and means normally maintainingsaid abutment means against said first stop means for resisting movementof said outer section to said abnormal position thereof.
 12. A safetyhelmet as defined in claim 11 wherein said means normally maintainingsaid abutment means against said first stop means comprises a springbiasing said abutment means against said first stop means whereby saidouter section moves against increasing spring reacation force as saidabutment means approaches said second stop means.
 13. A safety helmet asdefined in claim 12 wherein said first stop means is in the form ofspaced projections and said outer section includes a padding linerhaving grooves receiving said projections.